Lehr loaders or stackers, as they are sometimes termed, basically transfer a row of bottles moving at right angles to the movement of the lehr mat from the conveyor carrying the bottles by pushing the bottles from the conveyor onto the lehr mat. The motions of the bottle conveyors and the loader operation are synchronized for coordinated operation. In most glass forming operations, particularly of the individual section-type machines that are being used, the glassware is formed in the forming machine and then transferred to an annealing lehr for removing or relieving objectionable internal stresses and strains that are set up in the articles upon cooling of the article. If these stresses and strains are allowed to remain, the resulting articles are objectionably brittle and subject to excessive breakage during use. Where articles are produced in large quantities, it is most desirable, for efficient operation, that article handling be performed mechanically and preferably this means that the ware should be smoothly and automatically handled from the time that the ware is set out, from the forming machine onto a machine conveyor, to when the ware is transferred to a cross-conveyor. The cross-conveyor moves across the width of the lehr at the front end thereof and it is from this cross-conveyor that the lehr loader or stacker moves the newly formed ware into the lehr.
In the operation of present lehr loaders, there is the possibility that when the ware is fairly tall, with relatively small diameter bases, that the ware may tip as it is being transferred from the cross-conveyor to the moving lehr mat or belt.
It has been proposed to use a neck or finish stabilizing bar that is carried by the main pusher bar and to have this stabilizing bar pivoted to the pusher bar mounting so that it can be raised and lowered in time with the forward movement of the pusher bar.
One serious problem with such an arrangement, is that the stabilizing bar usually must be set so far ahead of the pusher bar that it loses its effectiveness and bottles will tip during transfer or if set too close will pivot down on to the top of the finish of the ware if the ware is pushed ahead of its normal line. This may occur when a serrated pusher bar is used. Further, the stabilizer could fall on the finish of some of the ware if the line of containers formed on the cross-conveyor were not accurately set in the proper line or not always in perfect alignment.
As previously stated, the ware is moved by a pusher bar engaging the sides of the ware at a point fairly close to the bottom of the ware. As the ware is moved from the cross-conveyor, it must move over a dead plate which extends between the side of the cross-conveyor and the lehr mat. Such an arrangement is generally shown in U.S. Pat. No. 2,547,791 dated Apr. 3, 1951.